netically engineered animal models for biomedical studies of human cancer for researchers at UVa and their collaborators in other academic institutions. The GTTF's mission is to support transgenic and gene targeting research endeavors, to ensure the most advanced technologies are available and to serve as a resource for these technologies. GTTF provides the following services: (1) transgenic mouse production;(2) chimeric mouse production; (3) gene targeting in embryonic stem cells;(4) transgenic embryo cryopreseration. These services are designed to expedite the process of animal model development and conservation, and maximize the use of resources. As a result of the facility's reorganizing efforts, the new director took over the position August 1, 2005. In order to expand the facility's service capabilities, the new director is in the process of establishing the following new services: (1) mouse ES cell line derivation;(2) mutant mouse assisted reproduction. The transgenic and gene targeting technology provides a powerful approach for cancer research. The use of transgenic and knockout mouse models of human cancer has proved invaluable for elucidating the functions of oncogenes and tumor suppressor genes, testing targeted therapies and imaging agents, and investigating complex oncogenic events in the whole animal.